Concrete mixer with tub lift



March 9, 1965 Filed Aug. 26, 1963 P. AUGUST 3,172,646

CONCRETE MIXER WITH TUB LIFT 3 Sheets-Sheet 1 March 9, 1965 P. AUGUST 3,172,646

CONCRETE MIXER WITH TUB LIFT Filed Aug. 26, 1963 3 Sheets-Sheet 2 March 9, 1965 P. AUGUST 3,172,646

CONCRETE MIXER WITH TUB LIFT Filed Aug. 26, 1963 5 Sheets-Sheet .3

IN VEN TOR United States Patent 3,172,646 CONCRETE MIXER WiTI-l TUE LIFT Paul August, Buenos Aires, Argentina, assignor to Inpaco Trust Reg, Vaduz, Liechtenstein Filed Aug. 26, 1%3, Ser. No. 304,358 Claims priority, application Germany, Apr. 24, 1963,

11 Claims. in. 259-160) The present invention relates to certain new and useful improvements in compulsory mixers of the type comprising a plate-shaped mixing receptacle.

The mixers of this type as hitherto known are very expensive for the following reasons: The mixer operates in horizontal position and its plate-shaped mixing receptacle must be arranged at a determined level high enough to permit the prepared mixture to be discharged into a pail, cart or the like placed below the discharge opening of said receptacle. In view hereof the mixer requires a tub lift for charging the mixing receptacle with the materials to be mixed. In addition hereto the mixer also requires a valve member for its discharge opening capable of maintaining the receptacle closed during the mixing operation. 7

Further, in view of the fact that modern mixers are electrically controlled by means of push button systems, three motors are required, viz. one for the tub lift, a second motor for the mixing device and a third one for the operation of the discharge valve. These three motors conveniently should be controlled semi-automatically by means of limit stopswitches. It is evident that such a mixer with tub lift, discharge valve and with additional motors for the operation of the tub lift and of the discharge valve and with control systems for three motors requires quite considerable expenses for these additional elements.

The present invention aims at providing a special mixer of the type referred to wherein the said expensive additional elements may be dispensed with and wherein but one motor is required with the advantageous. resuit that not only the weight of the mixer, but also the cost of manufacture of the same are considerably reduced.

Thus the main object of the invention is to provide a mixer, particularly for the preparation of concrete, mortar, asphalt and the like, comprising a plate-shaped mixing receptacle with a rotary mixing device, characterized in that said plate-shaped receptacle has a normally inclined position and is tiltably mounted on the machine frame and has a charging opening in its normally lower portion and a discharging opening in its opposite normally upper portion, and in that but one motor is provided and operatively connected with the mixing device in said receptacle and with a winch mechanism for lifting said receptacle to its discharging position.

The invention will now be described in detail with particular reference to the accompanying drawings which by way of example illustrate a preferred embodiment thereof, showing in: 7

FIG. .1 a schematic partly sectional side elevation of the improved mixer with the plate-shaped mixing receptace in its charging and discharging positions, the latter being indicated in dotted lines;

FIG. 2 a plan view of the mixing receptacle and its mixing device;

FIG. 3 a schematic side elevation illustrating the appli cation of the improved mixer to a so-called portal mixer.

Having reference to the accompanying drawings and more particularly to FiGURES l and 2, the mixer according to the invention comprises a plateshaped mixing receptacle 1 which is pivotally supported at 2. The pivot 2 is arranged in any suitable known manner on the ma- "ice chine frame 3 which conveniently is provided with an undercarriage 4. The mixing receptacle 1 in its charging and mixing position is inclined so that its charging opening 5 is situated at a low level, whereas its discharging opening 6 is situated near the pivot 2 at a high level. A motor with reduction gear indicated at 7 drives the shaft 8 of the mixing device in the mixing receptacle 1.

The shaft 8 carries a disk 9 to which a number of outwardly projecting arms ill is secured by screws or welding. These arms 10 are provided with cylindrical guide members 11 for the introduction of stud members 12 which carry the mixing shovels 13 and to which these shovels may be secured in any suitable manner, preferably by screwing said studs into screw-threaded sleeves formed by said shovels. The upper end portions of the studs 12 projecting beyond the upper surface of the arms iii are provided each with a transverse slot for receiving and retaining a leaf spring 14 which near its opposite end is guided between a pair of small studs or rollers 15. The slots of the studs 12 are cut in such an arrangement that part of the shovels 13 form approximately right angles with the side wall of the mixing receptacle 1, whereas the other shovels 13 are slightly inclined as shown in FIG. 2. In addition to the shovels 13 arranged close to the side wall of the receptacle 1 there are provided inner shovels 17 in different angular positions; these shovels 17 have about one half of the height of the shovels 13, but are also arranged near the bottom of the receptacle, whereas a second group of inner shovels 13 is arranged at certain distance from the bottom of the receptacle 1.

On the upper end of the shaft 8 there is provided a known freewheel hub 1% of a rope drum 20 which therefore is inoperative in one direction of rotation of said shaft 8. A rope or cable 21 is fastened at one end on the rope drum 20, passes around a guide pulley 22 and at its opposite end is secured at 23 to a bar member 24 which is mounted on the machine frame 3 preferably in a tiltable or removable manner. Except the charging opening 5, the top of the receptacle 1 is conveniently closed by a wire gauze or other sheet material.

if it is desired to use the mixer for the production of concrete destined for being transported by motor-trucks to difierent places of use, the plate-shaped mixing receptacle i as shown in FIG. 3 is combined with a machine frame 25 carrying an elevated silo an arranged at a level high enough to place a motor-truck below said silo. In this embodiment of the invention the plate-shaped recept acle 1 is provided with two pairs of carrier rollers 27 guided in U-ehaped guide rails 28. The receptacle 1 is lifted and lowered by a rope or cable 29 having one end fixed at St? and the opposite end on the rope drum 2%). The guide rails 2% bifurcate at 33,-the inner rails extending over the silo 25, whereas the outer rails form upstanding branches 31, the arrangement being such that the receptacle 1 is tilted when its discharging opening reaches its position above the silo 2d. 7

The operation of the mixer is as follows:

The materials to be mixed are introduced into the inclined mixing receptacle It in its lower position, preferably while the mixing device in said receptacle is rotating. Owing to the inclined position of the mixing receptacle, which if desired may be adjustable, the materials under treatment in the upper portion of the receptacle ire. near its discharging opening glide down. In view of the fact that the successive shovels 13 have different angles of incidence or attack, the material under treatment over certain shovels glides down faster than over the other shovels. The additional shovels 1'7 and 18 cause said material which moves downwards on the bottom of the receptacle to be subdivided and deviated in different directions. Further, by virtue of the fact that oneness one group of outer shovels 313 has a different angle of incidence or attack and that the shovels i7 and 13 are arranged at different levels, the resulting mixing opera tion is veryefiicient. Another advantage which also relates to an acceleration of the mixing process, as compared with the known mixers which also have a central drive and a plate-shaped mixing receptacle, consists in that according to the present invention the material under treatment constantly glides down and thus is continuously mixed with the material which simultaneously is conveyed upwards. Practical tests proved that the mixer according to the invention prepares a high quality mixture within about seconds.

As soon as the mixing operation is finished, the direction of rotation of the driving motor is changed so that now the rope drum 2! is caused to rotate and to wind up the rope or cable 21, thus lifting the mixing receptacle 1 to its upper discharging position in which as shown in FIG. 1, said receptacle operates a limit stop switch 34 which disconnects the motor and simultaneously changes its direction of rotation, so that the mixing receptacle is allowed to move to its charging position and the mixing device is again caused to rotate for the next mixing process. The mixing receptacle thus can be charged with new materials. The operator of the machine has nothing else to do but once per batch push the button of the control system and therewith start the discharging operation of the mixer. A second operator is not necessary at all; on the contrary the workman performing the charging of the mixing receptacle may also attend to the push button control.

The oscillatory arrangement of the shoxels 13 in the guide members 11 proved to be necessary in view of the fact that during the discharging operation stones of the concrete may become jammed between said shovels and the edge of the discharging opening. Owing to the provision of the leaf springs 14 the shovels 13 are allowed to slightly rotate and to release the jammed stones, whereafter said springs reestablish the normal position of said shovels.

Of course, the lifting and lowering of the mixing receptacle may also be carried out by hydraulic means.

By virtue of the very short mixing and discharging operations a very high output of the mixer may be readily attained.

A mixer according to the invention having a capacity of 200 liters, owing to its very simple construction, has a weight of about 750 kg. only and requires one motor of 6 H.P. As compared herewith the known mixers of the type in question of equal outputabout 12 to 15 m. /h.require three motors of 10, 4 and 3 H.P., respectively, and have a weight of about 2000 kg.

What I claim is:

1. A mixer, particularly for the production of concrete, mortar, asphalt and like mixtures, comprising a machine frame, a tiltable, normally inclined plate-shaped mixing receptacle supported by said frame, a charging opening in the normally lower portion of said receptacle and a discharging opening in the opposite normally higher portion of said receptacle, a rotary mixing device in said receptacle, including outer shovels arranged near the side Wall of said receptacle and rotatively secured to radial arms of a rotary disk and retained in their normal position by leaf springs, a driving motor operatively con nected with said mixing device and with a winch mechanism for moving said mixing receptacle to its discharging position.

2. A mixer as set forth in claim 1, wherein the said outer shovels are arranged under dilferent angles with regard to the side wall of the said mixing receptacle.

3. A mixer, particularly for the production of concrete, mortar, asphalt and like mixtures, comprising a machine frame, a tiltable, normally inclined plate-shaped mixing receptacle supported by said frame, a charging opening in the normally lower portion of said receptacle and a discharge opening in the opposite normally higher portion of said receptacle, a rotary mixing device in said receptacle, including outer shovels arranged near the side wall of said receptacle and rotatively secured to radial arms of a rotary disk and retained in their normal position by leaf springs, and inner shovels arranged under different angles of attack and at different levels with regard to the bottom of said receptacle, a driving motor operatively connected by a shaft with said rotary disk and with a Winch mechanism for moving said mixing receptacle to its discharging position.

4. A mixer, particularly for the production of concrete, mortar, asphalt and like mixtures, comprising a machine frame, a tiltable, normally inclined plate-shaped mixing receptacle supported by said frame, a charging opening in the normally lower portion of said receptacle and a discharging opening in the opposite normally higher portion of said receptacle, a rotary mixing device in said receptacle, including outer shovels arranged near the side wall of said receptacle and rotatively secured to radial arms of a rotary disk and retained in their normal position by leaf springs, and inner shovels arranged under different angles of attack and at different levels with regard to the bottom of said receptacle, a driving motor operatively connected by a shaft with said rotary disk and by means of a rope drum including a freewheel hub with a winch mechanism for moving said mixing receptacle to its discharging position.

5. A mixer as set forth in claim 4, wherein the said winch mechanism comprises the said rope drum, a rope and at least one guide pulley for said rope, the free end of which is fastened at a fixed point of the said machine frame.

6. A mixer as set forth in claim 4, wherein the said winch mechanism comprises the said rope drum, a rope and at least one guide pulley for said rope, the free end of which is fastened at a fixed point of a bar member secured to the said machine frame.

7. A mixer as set forth in claim 4, wherein the said machine frame includes guide rails for the said mixing receptacle.

8. A mixer for mixing concrete or the like and comprising, in combination, support means; a mixing receptacle on said support means; pivot means mounting said mixing receptacle on said support means tiltable between a loading and mixing position and a discharge position turned through an angle of substantially from said loading and mixing position; mixing means in said mixing receptacle for mixing a charge deposited in the latter; tilting means operatively connected to said mixing receptacle for tilting the latter about said pivot means; reversible motor means; and means connecting said reversible motor means to said mixing means and said tilting means for actuating said mixing means during rotation of said motor means in one direction and actuating said tilting means during rotation of said motor means in the direction opposite to said one direction.

9. A mixer, particularly for the production of concrete, mortar, asphalt and like mixtures, comprising a machine frame; a tiltable, pivotally mounted normally inclined plate-shaped mixing receptacle supported by said frame and having a disk-like bottom and a circular side wall perpendicular to said bottom; a rotary mixing device in said mixing receptacle and adapted to rotate in a plane parallel to said bottom; said mixing receptacle being formed with a charging opening in the normally lowor portion of the receptacle and a discharge opening arranged in said side wall at the normally higher portion of said mixing receptacle; a winch on said frame; and

a driving motor attached to said mixing receptacle and operatively connected with said mixing device and said Winch for moving said plate-shaped mixing receptacle from its inclined charging position to its oppositely in clined discharging position.

10. A mixer, particularly for the production of concrete, mortar, asphalt and like mixtures, comprising a machine frame; a tiltable, normally inclined plate-shaped mixing receptacle supported by said frame and formed with a charging opening in the normally lower portion of said receptacle and a discharge opening in a side wall of said receptacle at the opposite normally higher portion thereof; a rotary mixing device in said receptacle and including outer shovels arranged near the side wall of said receptacle at a given angle therewith and rotatably secured to radial arms of a rotary disk and retained in their normal position by leaf springs, and inner shovels arranged at a different angle with said side wall and at diiferent levels relative to the bottom of said receptacle; a driving motor attached to said mixing receptacle and having a shaft operatively connecting said motor with said rotary disk; a rope drum on said shaft; a winch on said frame and comprising a rope which is guided by a rope pulley provided on said mixing receptacle and which is fixed at one end to said rope drum and at the other end to a given point of said machine frame for moving said mixing receptacle from its inclined charging position to its oppositely inclined discharging poston about a fixed axis arranged at a point near the discharge opening of said mixing receptacle.

11. A mixer, particularly for the production of concrete, mortar, asphalt and like mixtures, comprising a machine frame including a pair of guide rails; a tiltably arranged, normally inclined plate-shaped mixing receptacle on said frame and having a disk-like bottom and a circular side wall perpendicular thereto; a rotary mixing device in said receptacle and adapted to rotate in a plane parallel to said bottom; said receptacle being provided with a charging opening in the normally lower portion thereof and a discharge opening in said side wall at the normally higher portion of said receptacle; at least two pairs of carrier rollers attached to the exterior surface of said bottom for movably supporting said mixing receptacle on said guide rails; said rotary mixing device including outer shovels arranged near the side wall of said receptacle at a given angle thereto and pivotally secured to radial arms of a rotary disk, and inner shovels arranged at a different angle to said side wall and at different levels relative to the bottom of said receptacle; a driving motor attached to said mixing receptacle and including a shaft operatively connected with said rotary disk; and a rope drum on said shaft for cooperating with a winch provided on said mixing receptacle and including a rope guided by a pulley, said rope having one end secured to said rope drum and the other end secured to a given point of said machine frame for moving the mixing receptacle along said guide rails from its inclined lower charging position to its oppositely inclined discharging position.

References Cited by the Examiner FOREIGN PATENTS 902,520 8/62 Great Britain.

CHARLES A. WILLMUTH, Primary Examiner. 

1. A MIXER, PARTICULARLY FOR THE PRODUCTION OF CONCRETE, MORTAR, ASPHALT AND LIKE MIXTURE, COMPRISING A MACHINE FRAME, A TILTABLE, NORMALLY INCLINED PLATE-SHAPED MIXING RECEPTACLE SUPPORTED BY SAID FRAME, A CHARGING OPENING IN THE NORMALLY LOWER PORTION OF SAID RECEPTACLE AND A DISCHARGING OPENING IN THE OPPOSITE NORMALLY HIGHER PORTION OF SAID RECEPTACLE, A ROTARY MIXING DEVICE IN SAID RECEPTACLE, INCLUDING OUTER SHOVELS ARRANGED NEAR THE SIDE 